What is the Drive Train loss %?

I figure 20% for some fudge factor.

I dynoed my Dakota and figured the loss on it to be about 25%, assuming the factory 220hp rating was correct. (4.7L Flex Fuel)

(166 RWHP * 100)/220 = 75% (25% loss)

Keep in mind that is a 4.7 with the 545RFE trans and a 9.25" truck rear end with 18" wheels, so I would expect the percentage loss to be a bit higher.

I think the 18-20% range is reasonable for a car based setup.